Glucosamine-6-phosphate-induced rate constant of riboswitch

Range ~100 min^-1
Organism Bacteria Bacillus subtilis
Reference Breaker RR. Riboswitches and the RNA world. Cold Spring Harb Perspect Biol. 2012 Feb 1 4(2). pii: a003566. doi: 10.1101/cshperspect.a003566. p.4 right column bottom paragraphPubMed ID21106649
Primary Source Brooks KM, Hampel KJ. 2009. A rate-limiting conformational step in the catalytic pathway of the glmS ribozyme. Biochemistry 48: 5669–5678. doi: 10.1021/bi900183r.PubMed ID19449899
Comments "One of the most interesting mechanisms for riboswitch mediated gene control integrates ligand binding and ribozyme activities (Fig. 2F). Representatives of the glmS riboswitch class function as metabolite-responsive self-cleaving ribozymes (Winkler et al. 2004). The ligand for this ribozyme-riboswitch is glucosamine-6-phosphate (GlcN6P), which is the metabolic product of the protein whose expression is controlled by the RNA. A glmS ribozyme construct from Bacillus subtilis cleaves with an GlcN6P-induced rate constant of nearly 100/min (primary source), which is an enhancement of more than 1 billion-fold above the rate constant for spontaneous RNA cleavage by phosphoester transfer. Ribozyme self-cleavage initiates rapid destruction of its associated mRNA coding region via selective nuclease degradation (Collins et al. 2007)."
Entered by Uri M
ID 110860